使用Python生成JSON数据

Question

I'm working on a little project, the aim being to generate a report from a database for a server. The database is SQLite and contains tables like 'connections', 'downloads', etc.

The report I produce will ultimately contain a number of graphs displaying things like 'connections per day', 'top downloads this month', etc.

I plan to use flot for the graphs because the graphs it makes look very nice:

This is my current plan for how my reports will work:

• Static .HTML file which is the report. This will contain headings, embedded flot graphs, etc.

• JSON Data file. These will be generated by my report generation python script, they will basically contain a JSON variable for each graph representing the dataset that the graph should map. ([100,2009-2-2],[192,2009-2-3]...)

• Report generation python script, this will load the SQLite database, run a list of set SQL queries and spit out the JSON Data files.

Does this sound like a sensible set up? I can't help but feel it could be improved but I don't see how. I want the reports to be static. The server they run on cannot take heavy loads so a dynamically generated report is out of the question and also unnecessary for this application.

My concerns are:

• I feel that the Python script is largely pointless, all of the processing performed is done by SQLite, my script is basically going to be used to store SQL queries and package up the output. With a bit more work SQLite could probably do this for me.

• It seems I'm solving a problem that must have been solved many times before 'take sql queries, spit out pretty graphs in a daily report' must have been done hundreds of times. I'm just having trouble tracking down any broad implementations.

Answer 1

It sounds sensible to me.

• You need some programming language to talk to SQLite. You could do it in C, but if you can write the necessary glue code easily in Python, why not? You'll almost certainly save more time writing it than you'll lose from not having the most efficient possible program.
• There are definitely programs to analyse logs for you - I've heard of Piwik , for instance. That's for dynamic reports, but no doubt there are projects to do static reports too. But they may not fit the data and output you're after. Writing it yourself means you know precisely what you're getting, so if it's not too much work, carry on.

Answer 2

I feel that the Python script is largely pointless, all of the processing performed is done by SQLite, my script is basically going to be used to store SQL queries and package up the output. With a bit more work SQLite could probably do this for me.

Maybe so, but even then, Python is a great glue language. Also, if you need to do some processing SQLite isn't good at, Python is already there.

It seems I'm solving a problem that must have been solved many times before 'take sql queries, spit out pretty graphs in a daily report' must have been done hundreds of times. I'm just having trouble tracking down any broad implementations.

I think you're leaning towards the general class of HTTP-served reporting. One thing out there that overlaps your problem set is Django , which provides a Python interface between database (SQLite is supported) and web server, along with a templating system for your outputs.

If you just want one or two pieces of a solution, then I recommend looking at SQLAlchemy for interfacing with the database, Jinja2 for templating, and/or Werkzeug for HTTP server interface.